Like radio, film, and theater companies going back hundreds of years, BioWare games often have a very familiar voice cast from one production to the next. A Dragon Age II player can't help but hear Varric's dry tones from the Male Trooper in Star Wars: The Old Republic, nor can a Mass Effect fan miss hearing Commander Shepard herself in, well, almost everything.

The voice cast of Mass Effect 3 is enormous, and ranges from the famous — like Seth Green, Martin Sheen, and Freddie Prinze Jr — to the utterly unknown. BioWare regulars pop up everywhere, alongside newer actors. Because of the branching nature of the story, which depends so much in part on the widely variable events of the first two games, it's literally impossible to see or hear everyone in a single playthrough. To go through every fan favorite and well-known guest star would be a million-word essay, but here's a look at a dozen of these hard-working behind-the-scenes folks, from the lead character to a few surprising, fun cameos.

UPDATE: We've corrected the image of Kimberly Brooks (Ashley Williams), which initially featured the wrong actress. Also, due to popular demand, we've added a few more comparisons and profiles to the gallery. Enjoy!

Mark Meer: Commander Shepard
One half of Commander Shepard is famous now, having graced game boxes and players' screens for five years. Meer's one of many familiar voices in the BioWare voice cast, appearing in the Dragon Age games as well as starring in the Mass Effect franchise. For those who have played Dragon Age 2, you can find him in the Blooming Rose brothel as Jethann the elf. Yes, really.

Jennifer Hale: Commander Shepard
It's a law: Jennifer Hale is in everything. She's like Nolan North that way. Lately she's best known as Commander Shepard, but before Mass Effect she was Metal Gear Solid's Naomi Hunter — and a whole lot more. She's been along for the BioWare ride for a decade, since the days of Baldur's Gate II and Knights of the Old Republic. Hale's been everything from Samus Aran to Cinderella and, in my personal favorite guest spot, one Avatar Kyoshi.

Raphael Sbarge: Kaidan Alenko
Sbarge has been featured as a character actor in countless television shows. And yet everyone who plays Mass Effect seems to say the same thing: "Hey, that's Carth! Carth Onasi! From Knights of the Old Republic!" And so he is.

(Sbarge photo: Courtesy of FanGeek.com)

Kimberly Brooks: Ashley Williams
Brooks hasn't had as many starring roles as some of the other Mass Effect cast, but she's been working in video games since the mid 90s. Like many of the ME3 cast, she appeared in smaller roles in Dragon Age: Origins and was most recently heard in Batman: Arkham City.

Update: we initially had a photo of the wrong Kimberly Brooks; there are two active actresses with that name and the trail of credits can be complicated to unravel. The correct Kimberly Brooks is now featured.

(Brooks photo: Courtesy of FanGeek.com)

Brandon Keener: Garrus Vakarian
I have to give enormous credit to everyone's favorite turian. Okay, my favorite turian. Garrus is full of character and personality even when his decidedly non-human face isn't easy to read. Keener's been performing in video games since the mid-2000s, and outside of the Mass Effect series is best heard in L.A. Noire.

Alli Hillis: Liara T'soni
Hillis has been busy in video games in the past few years. Not only has she given voice and soul to Dr. Liara T'soni, but also she performed the role of Lightning in Final Fantasy XIII and XIII-2. She can also be heard on television as Emma Frost in the X-Men.

Ash (Liz) Sroka: Tali'Zorah vas Normandy
Sroka is a young actress, whose career is still in its early stages. She took on the role of Tali in all three Mass Effect games, taking the character through a strong arc of growth.

Courtenay Taylor: Jack
Taylor began voice acting in video games roughly a decade ago, and has amassed a considerable pile of credits since. In addition to the Mass Effect series, she's had roles in Fallout: New Vegas and Alpha Protocol, as well as — like so very many others — MMORPG Star Wars: The Old Republic.

Keythe Farley: Thane Krios
Farley does less voice acting than many other members of the Mass Effect cast, but works very often with video game productions as a voice director. He worked as a voice over director for all games in the God of War series, among others, before giving a uniquely gravelly voice to the drell assassin.

Keith David: David AndersonCaptainCouncilor Admiral Anderson is a hell of a soldier, and always a moral support and even parental figure for Shepard. What he does not have is a sense of style, unlike actor Keith David. If Anderson's voice sounds familiar, it's because he has a list of film and TV credits dating back to the early 1980s. Child of the 90s that I was, my "Where have I heard this voice?" moment was me remembering his turn as Goliath in the late lamented animated series Gargoyles.

Armin Shimerman: Councilor Valern
Somehow, it never once occurred to me to look at the salarian councilor and wonder, "is that voice familiar?" More's the pity. Otherwise I'd have had a laugh knowing that Deep Space Nine's own profit-seeking Ferengi bartender Quark was behind that smug alien smoothness. Knowing Shimerman voiced the role makes me feel less annoyed about having saved the councilor's life. Twice.

Carrie-Anne Moss: Aria T'loak
Need a gangster who takes no crap from anyone and has the most violent scum in the galaxy firmly under her thumb? Then you need asari kingpin Aria T'loak, formerly of Omega. And who better to play a no-nonsense, take-no-prisoners leader than the biggest badass in The Matrix movies?

Sheen's career spans film and television going back to the 1960s. The versatile actor became famous with Apocalypse Now and has appeared in dozens of films since, and yet all the way through Mass Effect 2 I found myself thinking, "Oh, President Bartlet! Why so evil?

Michael Hogan: Armando-Owen Bailey
Canadian actor Michael Hogan's career goes back over thirty years, but to most of us nerd types he's the one and only Colonel Saul Tigh, from Battlestar Galactica. The voice is so familar that I keep expecting Commander Bailey to be bald and have an eyepatch. That head full of hair takes me by surprise every time I walk my Shepard into the C-Sec office. He also had a role in Fallout: New Vegas, where his character looked like desert doctor Tigh.

Seth Green: Jeff "Joker" Moreau
I always expect Joker to look more like Seth Green than he does, too, despite the fact that Green has been doing voice work for ages. Most popularly heard in Robot Chicken and Family Guy, Green lends much of the necessary tension-breaking humor to the Mass Effect series. Who knew spaceships benefited so strongly from being piloted by smartasses?

Tricia Helfer: EDI
One-time model Tricia Helfer seems to have found an unexpected niche portraying artificial life forms with genuine depth and emotion. After years spent playing many incarnations of Cylon model Six in Battlestar Galactica, she took on the role of disembodied ship-board AI EDI in Mass Effect 2. In ME3, EDI and her voice have rather more in common.

Freddie Prinze, Jr.: James Vega
I'll admit it: I actually forget to talk to Vega very often. I got into a Normandy-touring groove back in ME2 that only covered four decks, and I don't get my Shepard down to the suttle bay and armory as often as I should. It turns out, James is actually a pretty good guy, and Freddie Prinze, Jr. does a solid job bringing him to life. Although Prinze has been in a number of films, TV shows, and TV movies through the course of his career, ME3 is his first role in a video game.